Tach is reading wrong

[ejw24]

Noticed last night that the tach was sitting at "0" when the bike was at idle.  Had same problem today on the ride into work.  It seems to be off by approx 500rpm.  Any thoughts/ideas how to fix it or re-set it?  Damn frustrating as it seems like it's been a ton of little quirky things on the bike lately 

[Christian]

Which bike? Year, motor size?

[ejw24]

Which bike? Year, motor size?

'06 620 Monster

[Speeddog]

You can remove the bezel assembly and re-set the needle, the needles just pull straight off by hand.